1. Field of the Invention
The present invention relates to an ophthalmic apparatus for measuring a characteristic of an eye to be examined.
2. Description of Related Art
As an ophthalmic apparatus for measuring a characteristic of an eye to be examined, a refractmeter, an ophthalmometer, a keratometer, a tonometer and the like are widely known. Recently, a hand-held type apparatus has been provided allowing an easy and convenient measurement regardless of a posture of a patient (for example, an infant or a patient lying on his back).
This type of apparatus is usually provided with a measurement unit including a measurement part, and with a peripheral unit (including a printer, an external computer, another ophthalmic apparatus and the like) separately. The two units are, for example, connected via cable to transmit measurement data therebetween or the data transmission is done via wireless communications using infrared rays or the like for the sake of grater operativity and mobility of the measurement unit. In the case of transmitting measurement data to an external computer via wireless communications, the measurement data is first transmitted to a printer and then transmitted to the external computer from the printer.
In the above-described conventional art, however, to transmit measurement data to a printer or the like, all the data is formatted entirely on the side of the measurement unit before the transmission. This results in a great amount of the data so that it takes longer for the transmission, and that possibility of occurrence of a transmission error is increased. This is disadvantageous especially in wireless communications using infrared rays or the like. Although it is possible to adopt high-speed communications to shorten transmission time in the case of wireless communications, there are disadvantages of increasing the cost and shorten the communications distance.
Further, in the case of a hand-held type apparatus, it is relatively inconvenient to manipulate such an apparatus to carry out wireless communications. That is to say, after obtaining necessary measurement data, an examiner is required to turn a measurement unit toward a receiving end of an output device such as a printer, and then hold down a transmission button or the like that the measurement unit has until the transmission is completed.
Still further, in the case of transmitting measurement data to an external computer via wireless communications, it is inconvenient to carry out the transmission by way of a printer. In recent years, there have been computers provided with an infrared communications facility. Yet, most of these computers are compliant with the IrDA (Infrared Data Association) standard, which is the International Standard for infrared communications. Therefore, the computers are incapable of communications between a measurement unit and a printer if they do not meet the IrDA compliant, but their special standard.